Sound absorbing structure



J. MAZER SOUND ABSORBING STRUCTURE Jan. 29, 1957 2 Sheets-Sheet 1 Filed July 1'7, 1953 INVENTOR. Jqcos 96725. 2 BY Wm .bz's

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SOUND ABSORBING STRUCTURE Filed July 17, 1953 2 Sheets$heet Z 59 I" J4 I" -.l5. 16 55 -59 Y iiii;

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Zj'f'fi 81 Jr coa (7 1.252, r- 9 W: 11mm his (I TT'OQNEY SOUND ABSORBING STRUCTURE Jacob Mazer, Germantown, Pa.; Fannie Mazer, Ruth Mazer Simon, and Edna Mazer Rosenberg, executrices of said Jacob Mazer, deceased, assignors of twenty percent to Ruth Mazer Simon, twenty percent to Edna Mazer Rosenberg, and sixty percent to Ruth Mazer Simon and Edna Mazer Rosenberg, as trustees Application July 17, 1953, Serial No. 368,598

3 Claims. (Cl. 181-33) This application is a continuation-in-part of my applications Serial No. 91,955, filed May 7, 1949, now abannited States Patent Cir cloned, and Serial No. 134,923, filed December 24, 1949,

Patent No. 2,652,126, the present application containing description and claims to some non-elected species of the said applications, and also containing some modifications of those previous structures.

One object of my invention is to provide sound-absorbing units or structures that will function more effectively in the absorption and diffusion of sound waves of either high or low frequency than do various types of acoustical materials and structures heretofore employed, the invention being especially useful in the absorption of those sound waves of low frequency which have heretofore given more difiiculty than the high frequency waves.

Another object of my invention is to provide a soundabsorbing structure, wherein a single unit thereof has various degrees of flexibility under the impact of sound waves and may easily be altered to obtain predetermined sound-absorbing values.

Still another object of my invention is to provide a sound-absorbing structure that is so shaped as to more efiectively control the distribution or diffusion of those portions of the sound waves which are reflected instead of being absorbed, whereby there will be more uniform intensity of the sounds throughout a room in which the structure is used.

Some of the forms which my invention may take are shown in the accompanying drawings, wherein Figure 1 is a perspective view of one form of unit;

Fig. 2 is a fragmentary view showing more clearly a shape that is suitable for the individual sound-absorbing strips of Fig. 1;

Fig. 3 is a face view showing the manner in which a plurality of slabs each made of a group of strips such as those shown in 2 for example, may be mounted;

Fig. 4 is a sectional view showing a modification of e 3;,

Fig. 5 shows schematically a modification of the structure of Figs. 3 and 4, with the slab having its marginal I strips applieddirectly to-a wall or ceiling;

Figs. 6 and 7 are fragmentary face and end views respectively, of another form of unit; Fig. 8 being an edge view thereof;

Fig. 9 is a cross sectional view showing a modification of the structure of Figs. 68;

Figs. 10, 11 and 12 are face, end and side views respectively, of still another form of sound-absorbing unit or strip, and

Figs. 13, 14, 15, 16 and 17 show modifications of the structure of Figs. 10 to 12.

Referring first to Fig. l, the panel-like unit or slab is composed of strips 20 made of fibrous material after the manner of well-known fiber boards, or of other porous material of desired density or compactness, including matted fibers or felt, shaped to strip form and assembled in unitary relation and held loosely together as by wire stitching 21 or lightly glued together at spaced points, for

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the entry of sound waves between them and so that there will be a large capacity for sound-absorption between the loosely assembled, relatively-opposed faces of the strips. For example, open areas may be as shown at the openings or grooves 22 between the strips 23 of Fig. 2, or the spaces permissibly may be scarcely discernible, if the strips are only lightly held together, by stitching or glue, at spaced points, or in side-by-side relation and resting upon molding as in Fig. 4.

In Fig. 1, certain of the strips 20 extend farther rearwardly than the intermediate strips, for mounting against a base sheet similar to the backing sheet of Fig. 7 for example, or for direct connection to a wall face as in Fig. 5. The spaces formed between the strips 23 at their inner edges through the offsetting of the intermediate strips outwardly relative to the first-named strips serve to more effectively absorb sound waves that enter from the face of the unit and through the spaces 22.

Referring now to Figs. 3 and 4, I show, on a reduced scale, units that may suitably be composed of strips such as 23 or of other forms of strips somewhat loosely assembled, or entirely spaced apart as are some of the strips in Fig. 4. These strips are arranged somewhat in the form of slabs 25 supported in spaced relation to a wall, at suitable intervals, by molding 26, or they may be applied directly to a wall surface or backing sheet. This arrange ment gives a tile-like effect that is frequently desirable from a decorative standpoint, in addition to an increased sound-absorbing effect. The irregular spaces as at 22 are important in diffusing and absorbing sound waves, even if the sides of the strips that define said spaces are smoothsurfaced.

In Fig. 5 is shown a somewhat schematic arrangement that provides, as in Figs. 1 and 4, space at the rear of the unit for the more effective absorption of sound waves that enter between the strips 23 and 29. The strips 28 are shown as glued, cemented or otherwise fastened to a wall or ceiling surface 30 and the strips 28 and 29 may be connected together by stitching or gluing as above mentioned. In this arrangement, the exposed faces of the strips are shown as curved so as to give the desired deflection to sound waves, somewhat after the manner of the outwardly-projected side areas of certain of the strips of Fig. 1.

Referring now to Figs. 6, 7 and 8, I show a unit having a backing sheet or base sheet 32 to which a sheet or sheets of corrugated board 33 is applied, there being a smooth sheet 34 to which the corrugated sheet 33 is adherently connected in the usual manner. The arrangement is such as to form, in effect, ribs having hollow spaces 35 between the sheet 34 and the base 32. The large ribs shown in Fig. 7 may be separately formed or made from continuous sheets as shown in the drawing. Holes 36am provided through the sides of the ribs, for the entry of sound Waves into the spaces 35 or may be omitted. The exterior surfaces of the ribs, of course, effect diffusion of sound waves in a multitude of directions, while a large portion of the sound waves is absorbed within the spaces 35, owing to the flexibility and yieldability of the members 33 and 34. The corrugations 33 individually are effective in absorbing sound waves of various frequencies, while the large ribs, as a whole, are more effective in absorbing sound waves of the lower frequencies.

In Fig. 9, a modification of the structures of Figs. 6 to 8 is shown. In this case, a backing sheet or wall surface 38 has applied thereto channel members 39 and 41B of acoustical material such as soft, flexible, fibrous sheets of rag felt, paper, asbestos, glass fibers, and the like. These channels may be made integrally with one another, or separately, and provided with holes or perforations 41 through their side Walls (though the holes need not be provided) and are additionally ribbed or corrugated 'sorbing the higher frequencies. contribute toward the admission of some of the sound waves into the spaces where the inner walls of the channels furnish almost as much exposure for the absorption of sound waves as their exterior surfaces. The ribs 42 provide for diffusion in directions other than that effected by the perpendicular sides of the channels.

Figs. 10 to 12 show a unit or strips having a base sheet 44 to which are connected sheets 45 each having accordion-like folds therein to make it of generally hollowribbed form and to give flexibility. The convex side of the ribs form overhangs behind which sound waves will 7 be absorbed. This strip may be of fibrous sheet material or other material that has greater stiffness than .its covering or facing strip 46 that i unitarily connected thereto at various points and which is made water-repellent, by the use of silicons or other materialthat will not detract materially from its soft nature, and it may suitably be made of asbestos fibers. Holes 47 are provided for the freer entry of sound wave into the channel-like spaces, when desired. The covering strip 46 is connected to the strip 45 at only small areas, so as to not materially .detract from the flexibility of the'rib as a whole, under the impact of sound waves.

Referring now to Fig. 13, I show an arrangementsomewhat similar to that ofFig. 11, in that a laminated hollow rib arrangement comprising a bent strip 48 and a covering strip 49 are connected to base sheet 50. In this case, however, the base sheet is applied in convex shape to a wall 51', so that a space is left into which sound waves may enter because of the porosity. and movements of the flexible walls that form the hollow ribs, and also through holes 52 and 53 for increased absorption within the hollow rib structure 4849. in this caseas in Figs. 9 and 10, there are crosswise corrugations or ribs as indicated at 54 for increased absorption and diffusion of sound Waves in a multiplicity of directions.

In both the structures of Figs. 11 and 13, the covering strips 46 and 54 respectively, may be of crepe-like, finish for increasing the difiusive capacity of. the structure.

Referring now to Figs. 14, 15, 16 and 17, I show modifications of the structures of Figs. 11 and 13 in that the hollow ribs are, of multi-layer structure, the two strips of each rib being loosely associated so that they may flex independently of each other and will effectively dampen or absorb sound waves whether or not any holes are provided as in Fig. 12. Thus, in 14, we have an innerlayer 56 secured to a backing sheet or base 57, andan outer layer 58 loosely connected to the inner layer or to the backing sheet. In Fig. 15, the inner and outer loosely-associated layers are represented by the numerals 59 and 60 respectively. In Fig. 16, these members are shown at 61 and 62, and in Fig. 17, by the numerals 63 and 64. Also, in Fig. 17, I show the hollow rib filled with fibrous material .65 which may suitably beef mineral wool or the like. The various hollow ribs of the other figure may be filled in like manner.

While materials of. various degrees of density, such as those mentionedin mysaid applications, may be employed in the practice of this invention, materials of low density will be more suitable for general use; for example, a fibrou or porous material having a density of .5 or less, viz, materials weighing 31 lbs. per cubic foot or less will give good results. 7

It will be understood that the term wall is used in a broad sense in the accompanying claims, and it is contemplated the units shall be applied to walls, ceilings, columns, or even mounted inspaced relation to such surfaces.

I claim as my inven-tionz 1. A sound-absorbing panel-like unit that comprises strips of low density sound-absorbing material held loosely engaged with one another in'side-by-side relation, alternate strips having their rear edges in approximately a common plane for connection to a wall surface, and the intermediate strips being set outwardly relative to said plane and unitarilyconnected with the said alternate strips, whereby sound waves which pass rearwardly through the areas between the strips will be entrapped in the spaces behind the rear edges of the said intermediate strips.

2. A unit as .recited in claim 1, wherein the sides of the strips are of wave-like form, the curvatures being about axe .which are perpendicular to the said plane.

3. A unit as recited in claim 1, wherein the intermediate strips project outwardly beyond the said alternate strips.

References Cited in the file of this patent UNITED STATES PATENTS 509,446 OShea Nov. 28, 1893 1,483,366 Mazer Feb. 12, 1924 1,628,090 Weiss May 10, 1927 1,782,399 Amy Nov. 25, 1930 1,875,074 Mason Aug. 30, 1932 1,975,637 Finley Oct. 2,1934 2,161,708 Heerwagen June 6, 1939 2,250,683 Slechta July 29, 1941 2,341,305 Woodworth Feb. 8, 1944 2,357,560 Taforo Sept. 5, 1944 2,390,262 Mazer Dec. 4, 1945 2,413,331 Munters Dec. 31, 1946 2,590,204 Phillips Mar. 25, 1952 2,652,126 Mazer Sept. 15, 1953 2,692,547 Ericson Oct. 24, 1954 FOREIGN PATENTS 542,819. Germany 12111.30, 1932 

